DOI Links for Encyclopedia Articles

Since 11/2023, each article of the RP Photonics Encyclopedia is equipped with a digital object identifier.

The Concept of Digital Object Identifiers

Some background information on that concept:

We assign a string of characters called a Digital Object Identifier (DOI) to each article. The DOI consists of a prefix that identifies the publisher (e.g. 10.61835 for RP Photonics), followed by a slash and a suffix that identifies the specific article. This identifier must be unique and permanent.
Example: the DOI 10.61835/gps belongs to our article on adaptive optics.
Note that the strings are randomly created and meaningless. In the above case, for example, gps has nothing to do with the global positioning system.
Furthermore, there is a digital infrastructure that allows anyone to retrieve the article using only the DOI. This infrastructure is run by the doi Foundation. The use is simple: take the base URL https:/doi.org/ and add the DOI to it. This results in a URL that the DOI system redirects to the actual article page.
For example, the following DOI link points to our article on adaptive optics: https://doi.org/10.61835/gps
If the article ever needs to be moved to a different location on the Internet, that new location can be stored in the DOI system so that the redirects work as before; there is no need to update links everywhere in the Internet. Obviously, this helps ensure permanent accessibility.
The DOI system actually stores much more detailed information than just page URLs: a rich set of metadata that is useful for various other purposes.

RP Photonics is a member of Crossref, an organization specifically for scholarly publishers, and through Crossref we interact with the doi Foundation. We keep this information up to date, for example by reporting DOIs for our new articles. Crossref submits this information to the doi Foundation.

Using DOI Links

When citing our encyclopedia articles or placing links to them on the Internet, you can still do so the old way, using our page URLs directly. However, we now encourage you to use the DOI links instead – even though we are unlikely to move the articles elsewhere for the foreseeable future.

Our citation tool (see the box below each article heading) also uses DOI links.

By publishing DOI links, we are emphasizing that our articles can (and often should) be cited; we are ensuring the continued accessibility of the content.

We have been using DOIs in our article bibliographies for several years already. Before that, a change in the link structure of one publisher forced us to correct a lot of links, and before that, we had broken links. This can no longer happen as we use DOIs wherever possible. Most scientific publishers provide DOI links for all their articles.